Fork

Allows workflows to execute multiple subtasks concurrently, enabling parallel processing and improving the overall efficiency of the workflow. By defining a set of subtasks to perform concurrently, the Fork task facilitates the execution of complex operations in parallel, ensuring that multiple tasks can be executed simultaneously.

Properties

Name	Type	Required	Description
fork.branches	map[string, task]	no	The tasks to perform concurrently. These will be run as child workflows.
fork.compete	boolean	no	Indicates whether or not the concurrent tasks are racing against each other, with a single possible winner, which sets the composite task's output. If set to false, the task returns an array that includes the outputs from each branch, preserving the order in which the branches are declared. If to true, the task returns only the output of the winning branch. Defaults to false.

Example

Non-competing Fork

info

This is the default behaviour.

This will return all the workflow.

document:
  dsl: 1.0.0
  namespace: zigflow
  name: example
  version: 0.0.1
do:
  - raiseAlarm:
      # A fork is a series of child workflows running in parallel
      export:
        as: raiseAlarm
      fork:
        # If not competing, all tasks will run to the finish - this is the default behaviour
        compete: false
        branches:
          # A single step is passed in by the Serverless Workflow task - this will be implicitly wrapped in a Do task
          - callNurse:
              call: http
              export:
                as: callNurse
              with:
                method: get
                endpoint: https://jsonplaceholder.typicode.com/users/2
          # Multiple steps can be passed in by the Serverless Workflow do task
          - multiStep:
              do:
                - wait1:
                    wait:
                      seconds: 3
                - wait2:
                    wait:
                      seconds: 2
          # Another single step child workflow - this will be implicitly wrapped in a Do task
          - callDoctor:
              call: http
              export:
                as: callDoctor
              with:
                method: get
                endpoint: https://jsonplaceholder.typicode.com/users/3

This will output an object similar to this, with the workflow data under the raiseAlarm key:

{
  "raiseAlarm": {
    "callDoctor": {
      // The workflow's data
    },
    "callNurse": {
      // The workflow's data
    }
  }
}

Competing Fork

This will return the fastest returning workflow only. Simply change compete: false to compete: true. The data will look similar to this:

{
  "raiseAlarm": {
    // The workflow's data
  }
}

Unlike the non-competing version, the raiseAlarm object will ONLY contain the data of the winning fork. All the other workflows will be cancelled and any data generated will be discarded.